Controversial Australian Nick Kyrgios has issued an apology after storming off court and quitting the Shanghai Masters having lost a first-set tie-break to world No45 Steve Johnson yesterday.

Kyrgios was visibly frustrated after challenging a line call and having the decision overturned, while he was deducted a point for yelling an expletive at the judge.

After Johnson served an ace to seal victory in the tie break, Kyrgios walked to the net and offered his hand to his rival before proceeding to walk off court to boos from spectators.

“Guys, I want to apologise to the fans in Shanghai and those that watched around the world on TV,” read a statement from Kyrgios.

“I’ve been battling a stomach bug for the past 24 hours and I tried to be ready but I was really struggling on the court today which I think was pretty evident from the first point. My shoulder started to hurt in practice which didn’t help either.”

It is not the first time Kyrgios has landed himself in hot water at the Shanghai Masters. Last year he was fined $25,000 and handed an eight-week ban due to his behaviour, which included a “lack of his best efforts”.